Trailer Tire vs. Trailer Wheel Weight Carrying Ratings

Question:

I have been told too many answers to the problem I will outline with your expert answer on your site adding to the confusion. You are referencing a wheel, AM20422, a 15x5-5/4.5 which shows a weight rating of 1820 lbs. In your reply to another person you state any 205/15 tire in C or D will work on that wheel. Ok, are you saying it will be ok to run a tire with a weight rating of 2150 lbs on a wheel that only shows a rating of 1820 lbs?? Can it be done safely and legally is my question. I currently have a travel trailer that came with C rated 205x15Rx15 tires with the wheels showing 1820 lbs on them but I would like to put a D range on them for the extra strength sidewall it offers. Not increasing the trailer GVWR just wanting to upgrade the tires to a stronger more dependable one. Please urgently shed some light on this type situation ass I need to re-tire my camper soon...P.S. I am a fanatic about maintaining tire pressures correctly.

asked by: Ted H

Expert Reply:

If a trailer tire and wheel each have different weight capacities then the lower-rated item of the two determines the overall capacity of the combination. You can certainly run a tire with a lower or higher weight rating than the wheel its used on but you will be limited to the capacity of the lower-rated component. The key for safe and legal trailering is to ensure that the lowest-rated component is rated adequately for the load on it. Extra capacity in other components is fine but you're limited by the lowest-rated item.

Its great that you keep your trailer tire pressure spot on the rated psi shown on the tires. This is very important for getting the most out of the tires. They will not deliver their rated capacity unless inflated to their maximum pressure as noted on the sidewall.

The linked articles on trailer tires and wheels may be of interest to you.

expert reply by: Adam R

Dave J.

3/5/2020

Can I upgrade tires on a fifth wheel toy hauler from a E rated tire carrying 80 psi to a G rated tire carrying 110 psi without upgrading the wheels. Valve stems have already been up graded to high pressure valves.

Chris R.

3/5/2020

The valve stem is almost always the determining factor when it comes to the psi rating of a trailer wheel. As long as the new valves are up to the task, the higher psi won't be a problem for your existing wheels.